GFS2: eliminate log elements and simplify

This patch eliminates the gfs2_log_element data structure and
rolls its two components into the gfs2_bufdata. This makes the code
easier to understand and makes it easier to migrate to a rbtree
to keep the list sorted.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/lops.h b/fs/gfs2/lops.h
index 825356d..954a330 100644
--- a/fs/gfs2/lops.h
+++ b/fs/gfs2/lops.h
@@ -46,17 +46,17 @@
 	return limit;
 }
 
-static inline void lops_init_le(struct gfs2_log_element *le,
+static inline void lops_init_le(struct gfs2_bufdata *bd,
 				const struct gfs2_log_operations *lops)
 {
-	INIT_LIST_HEAD(&le->le_list);
-	le->le_ops = lops;
+	INIT_LIST_HEAD(&bd->bd_list);
+	bd->bd_ops = lops;
 }
 
-static inline void lops_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
+static inline void lops_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 {
-	if (le->le_ops->lo_add)
-		le->le_ops->lo_add(sdp, le);
+	if (bd->bd_ops->lo_add)
+		bd->bd_ops->lo_add(sdp, bd);
 }
 
 static inline void lops_before_commit(struct gfs2_sbd *sdp)